ALL BG MUSIC AND REMIXES FROM PANTY AND STOCKING! Can't believe no one said this yet!!!!!

I totally forgot about the panty and stocking music. I bought the album from Japan and I listen to it weekly. I think I forgot about it because the music doesn't sound like any other anime music...and then I forget I'm listening to an anime soundtrack. The album is full of really good electronic music like house, dance and dubstep. Probably the best anime soundtrack I have ever heard.

The one I particularly like right now it Balance Doll by Prague for the current Gintama ED. Bad thing is, it isn't going to come out until 10th August! *Plays ending of Gintama over and over and over...*

Yes, that may be a rather vague question but should be simple enough to answer. You can of course have more than one answer and should post links to help expand the discussion. The song can be from an OST, ED, OP or moreover, anything that has to do with an anime. It should be songs that strictly comes from an anime and one that should be important enough that you can label it your personal favorite. The conversation should be about specific songs and not anime soundtracks as a whole and include your reasons for liking the song(s).

Two of my very favorites are Sokushin Butsu Hakushin Shounin by Kaoru Wada from Inuyasha OST 3 and Instant Music by The Pillows from the first OST of FLCL. The first song just gives me this very melancholy and contemplative feeling that no other song has before and makes me extremely grateful that I like anime or I would have never discovered music like this. While Instant Music is something I can literally listen to over and over and in my opinion is a perfectly constructed pop song. So post your favorites and rock on!